Optimal reactive power planning in distribution system with wind power generators

The active power output of the wind power generators is calculated by the probability of running state, and the expectations of active power are used to replace the randomly changing output. Considering light, normal, and heavy load operation mode, the mathematical model has been established. In the heavy load operation mode, the multipurpose optimal model is proposed which aims to minimize the investment cost, maximize the level of static voltage stability and the savings in energy cost, the problem is solved by NSGA-II algorithm. In the light and normal load operation mode, the optimal model is proposed which aims to maximize the savings in energy cost. The three operating modes are coordinated by the maximum savings when reactive power has been compensated, the optimum allocation of the capacitor is obtained, and the whole optimization is realized. An example verifies the feasibility of the model and the algorithm.